Over the years, wind turbines have become increasing popular for providing a relatively inexpensive source of electrical energy. With this growing interest, considerable efforts have been made to develop wind turbines that are reliable and efficient.
In general, most wind turbines comprise a rotor that is generally mounted to a tower or other structure. A plurality (often three) of long blades are mounted to the rotor and are oriented such that wind contact with the blades imparts a rotational motion to the rotor. In short, the blades transform wind energy into a rotational torque or force that drives one or more generators that are operably coupled to the rotor through an arrangement of gears. The gears convert the inherently slow rotational speed of the rotor to a rotational speed which can be advantageously used by a generator to generate electrical energy. Gearless direct drive turbines also exist.
One problem often encountered when using wind turbines is the accumulation of ice on the turbine blades. Icing frequently adversely affects performance of the wind turbines during winter seasons. For example, at times, icing may be so severe that it prevents the turbines from producing power despite the existence of ideal wind conditions. In addition, build-up of ice on the blades may cause the rotor to become imbalanced and thereby place undesirable stress on the blades and the drive system. In those applications wherein the wind turbine is operating in a remote, unmonitored area, the turbine's diminished effectiveness due to icing may largely go undetected. In severe cases, the turbine may fail to produce the electricity need to keep critical monitoring and other equipment operating. If there is no personnel on site to monitor and remedy the condition, catastrophic results may occur. Even in applications wherein the wind turbine is constantly monitored, the environment and the manner in which the turbine is mounted may make servicing difficult.
Over the years, a variety of different solutions have been developed for deicing wind turbine blades. For example, some devices require the use of resistive heating wires on the blades. Other approaches involve the application of inflatable boots, alcohol, heat, etc. to the blades. Such approaches enjoy varying degrees of effectiveness. However, these approaches typically involve the use of additional equipment which ads expense to the turbine and are largely ineffective on turbines that are located in remote locations and are not easily accessible for maintenance purposes.
In addition, the masts that support the wind turbines must be designed to withstand the loads resulting from a maximum expected level of wind speed. Thus, those wind turbines that are located in locations wherein high wind speeds may be encountered often require complex and extensive mounting mast arrangements.
Thus, there is a need for a wind turbine blade arrangement that is configured to prevent the build-up of ice on the blades without the use of additional electrical, air powered, or chemical equipment.
There is a further need for a wind turbine blade arrangement that serves to reduce the wind loading experienced by the support mast.
The foregoing discussion is intended only to illustrate some of the shortcomings present in the field of the invention at the time, and should not be taken as a disavowal of claim scope.